Male Hypogonadism

What hypogonadism is

Hypogonadism in men is the combination of a testicular failure to produce enough testosterone, sperm, or both, with the symptoms and signs that failure causes. The word describes a state of the whole axis — hypothalamus, pituitary, testes — not a number on a lab report. This distinction is doing more work than it sounds like: a low testosterone result with no symptoms is not hypogonadism, and symptoms with a normal testosterone are not hypogonadism either.

The first thing a clinician establishes after confirming the deficiency is where in that axis it arises. Primary hypogonadism is testicular: the testes cannot make testosterone, and the pituitary shouts louder, so luteinising hormone and follicle-stimulating hormone run high. Secondary hypogonadism is central: the signal from the pituitary or hypothalamus is weak or absent, so LH and FSH are low or inappropriately normal. The two are distinguished by a blood test, and they lead to different investigations — a man with unexplained secondary hypogonadism may need his prolactin, his iron studies and sometimes an MRI of the pituitary.

The second distinction matters more for most men reading this. The Endocrine Society splits causes into organic and functional: "Organic hypogonadism (also referred to as “classical” hypogonadism) is caused by a congenital, structural, or destructive disorder that results in permanent hypothalamic, pituitary, or testicular dysfunction (primary or secondary hypogonadism). In contrast, functional hypogonadism is caused by conditions that suppress gonadotropin and T concentrations but that are potentially reversible with treatment of the underlying etiology." Severe obesity, opioids, glucocorticoids, uncontrolled diabetes, systemic illness and some sleep disorders are all on the functional list. In those men the low testosterone is a consequence of something else, and treating the something else is the treatment.

That is why the order of the evaluation matters. A man who is given testosterone for a low result caused by untreated sleep apnoea has had his number corrected and his actual problem left in place — and testosterone therapy suppresses his own production and his fertility while it runs.

Why the symptoms cannot settle it

The symptoms attributed to low testosterone are fatigue, low mood, poor concentration, reduced strength, increased body fat, disturbed sleep, low libido and erectile dysfunction. Read that list again and notice that every entry except the last two is also a symptom of depression, of poor sleep, of hypothyroidism, of anaemia, of being forty-five and under-slept. That is not a criticism of the list. It is the finding.

The Endocrine Society states it directly: "The symptoms and signs of T deficiency are nonspecific and modified by age, comorbid illness, severity and duration of T deficiency, variations in androgen sensitivity, and previous T therapy." It then adds something almost nobody quotes — "there are no population-based surveys of symptoms and signs in men with the full spectrum of severity of hypogonadism". The canonical symptom list was assembled from the clinical experience of severely deficient men and from what improved when they were treated. It was never validated as a way of identifying the mildly affected man reading a web page.

The European Male Ageing Study is the largest attempt to test the association empirically: 3,369 men aged 40 to 79 across eight European centres, testosterone measured by mass spectrometry on morning samples. Six symptoms tracked with testosterone level — "poor morning erection, low sexual desire, erectile dysfunction, inability to perform vigorous activity, depression, and fatigue". But when the authors asked which of them clustered together as a syndrome rather than merely correlating individually, the answer narrowed sharply: "only the three sexual symptoms had a syndromic association with decreased testosterone levels". Fatigue, low mood and poor concentration did not survive. Those are exactly the three symptoms that bring most men to search for this in the first place.

And even the three that survived do not stand alone. EMAS concluded: "Late-onset hypogonadism can be defined by the presence of at least three sexual symptoms associated with a total testosterone level of less than 11 nmol per liter (3.2 ng per milliliter) and a free testosterone level of less than 220 pmol per liter (64 pg per milliliter)." The symptoms are one of three required components, not a shortcut to the other two.

The signs that are specific — and none of them are self-assessable

Incomplete or delayed sexual development

A history of puberty that did not arrive or did not complete. This is a history a clinician takes, not something assessed retrospectively from a web page, and it points towards congenital causes that need a different workup entirely.

Loss of body (axillary and pubic) hair

Loss of already-established secondary sexual hair, which is a different observation from male pattern baldness or from never having had much. Androgenetic alopecia is not a sign of hypogonadism.

Very small testes

Testicular volume under 6 mL. This is measured with an orchidometer during a physical examination; it is not something to estimate at home, and the Endocrine Society treats a volume this low as a prompt to obtain a karyotype to look for Klinefelter syndrome.

The diagnostic criteria, quoted

Each criterion below is the guideline’s own wording, not a summary of it. Our reading follows underneath, so you can weigh one against the other.

1. Both halves are required — a number alone is not a diagnosis

   “We recommend diagnosing hypogonadism in men with symptoms and signs of testosterone deficiency and unequivocally and consistently low serum total testosterone and/or free testosterone concentrations (when indicated).”

   Three words in that sentence are load-bearing and get dropped in every summary of it. "Unequivocally" rules out a result sitting just under the line. "Consistently" rules out one result. "And" rules out diagnosing from either half alone. The AUA states the same requirement from the other direction: "Total testosterone <300 ng/dL alone does not define testosterone deficiency."

2. Two samples, both in the morning

   “Testosterone concentrations exhibit significant diurnal and day-to-day variations and may be suppressed by food intake or glucose. Therefore, clinicians should measure total testosterone concentrations on two separate mornings when the patient is fasting.”

   The AUA requires the same two morning draws: "The diagnosis of low testosterone should be made only after two total testosterone measurements are taken on separate occasions with both conducted in an early morning fashion." It disagrees about fasting — see the section below. Neither guideline specifies how far apart the two draws should be, and the AUA says why: "At this time, there is no definitive evidence indicating what the optimal time interval should be between the two separate tests."

3. Why one low result is not enough

   “It is important to confirm low T concentrations, because 30% of men with an initial T concentration in the hypogonadal range have a normal T concentration on repeat measurement”

   This is the single most useful figure on the page. Roughly one man in three whose first test comes back low will test normal on a second morning sample, with nothing having changed but the day. If you were diagnosed on one result, that is the number to bring to the conversation.

4. Do not test during illness, or on certain medications

   “Clinicians should not test men for testosterone deficiency who have or are recovering from an acute illness or are engaged in short-term use of medications (e.g., opioids) that suppress testosterone concentrations.”

   A result drawn in the wrong week measures the illness. The AUA quantifies it: "In a small study of young men with acute respiratory infections, mean total testosterone levels declined by 10%, with some cohorts experiencing reductions of up to 30%." A man tested during a chest infection can be moved across either threshold by the infection alone.

5. When free testosterone is measured, and how

   “Clinicians should not use direct analog-based free testosterone immunoassays, as they are inaccurate.”

   Free testosterone is indicated when something alters sex hormone-binding globulin — ageing, obesity, diabetes, thyroid disease, HIV, liver disease, some anticonvulsants, glucocorticoids — or when total testosterone lands in the borderline zone the guideline gives as roughly 200 to 400 ng/dL. It should come from equilibrium dialysis, or from a calculation using total testosterone, SHBG and albumin. The cheap direct assay that many panels include is named and rejected.

6. Then: primary or secondary

   “Measuring LH and FSH concentrations can help distinguish between primary and secondary hypogonadism”

   This step is skipped constantly, and skipping it is how a pituitary tumour gets treated as low T. The AUA makes it a Strong Recommendation, Grade A: "In patients with low testosterone, clinicians should measure serum luteinizing hormone levels." High LH means the testes; low or inappropriately normal LH means the pituitary or hypothalamus, and prompts prolactin, iron studies and sometimes imaging.

7. And: no screening of men who have no reason to be tested

   “We recommend against routine screening of men in the general population for hypogonadism.”

   The AUA agrees and says it about the patient in front of you: "Clinicians should refrain from measuring testosterone levels in patients who are asymptomatic, do not exhibit signs related to low testosterone, or do not have any comorbid conditions that are associated with low testosterone." This is worth knowing before buying a testosterone panel out of curiosity. A population where the condition is rare generates mostly false positives, and a false positive here ends in a prescription that suppresses your own production.

Where the guidelines disagree

On these points there is no consensus to report. Both positions are printed with the wording each body used.

Diagnostic thresholds for low testosterone, by guideline

Every total testosterone threshold a major body has published for this diagnosis, in both units, with what each one actually requires alongside the number. They do not agree, and that is the point of the table.

The EMAS figure is 11 nmol/L converted, not a separately published ng/dL number, and it is a research definition of late-onset hypogonadism rather than a clinical cutoff. The AUA guideline records that societies have used thresholds "ranging from 230-350 ng/dL"; this page prints the three that are traceable to a primary document we opened, and no single number is presented as the answer. Conversions are computed by the same function /tools/testosterone-unit-converter uses. Sources: [2] [3] [5]

The harmonized reference distribution — where any threshold sits

The published centiles for total testosterone in healthy nonobese men aged 19 to 39, harmonized to the CDC reference method. Both candidate lower limits are centiles of this one distribution.

From Travison 2017, which pooled four cohorts and re-measured a subset of each at the CDC to put them on a common scale. Note what the first two rows mean together: 264 and 303 ng/dL are the 2.5th and 5th centiles of the same men. The gap between the Endocrine Society and the AUA is largely a gap between two conventional cut points on one curve, not between two different bodies of evidence. This is a young-men reference sample by construction; it is not age-adjusted, and no body has established an age-adjusted diagnostic threshold. Sources: [4] [2]

What moves a testosterone result besides testosterone

Published magnitudes for the things that change the number without changing the man. Read this before reading any single result, including your own.

These are not rounding errors. The assay spread alone — one sample, 1,133 laboratories, results from 45 to 365 ng/dL — is wider than the entire distance between the two guideline thresholds. A result is a measurement of a man on a morning in a laboratory, not a property of the man. Sources: [2] [3]

The tests, and what each one answers

Things that are not hypogonadism and look exactly like it

This list is the practical reason the diagnosis needs a clinician rather than a blood panel. Every entry can produce the fatigue, low mood, low libido and reduced physical performance that bring men here, and several of them also genuinely lower testosterone — which means a low result confirms nothing about the cause. The Endocrine Society groups most of them as functional hypogonadism: real suppression, potentially reversible by treating what is causing it.

Depression and chronic stress

The AUA names this explicitly: men reporting mood change, poor concentration, loss of strength, increased fat, erectile dysfunction or low libido "may exhibit these symptoms secondary to chronic stress, chronic fatigue, or depression rather than due to low testosterone levels". Depressed mood is also on the Endocrine Society’s own non-specific symptom list, which is precisely why that list cannot discriminate.

Obstructive sleep apnoea and other sleep disorders

Listed by the Endocrine Society among the functional causes of secondary hypogonadism, and independently a cause of daytime fatigue, low mood and poor concentration. Untreated severe obstructive sleep apnoea is also a condition in which the same guideline recommends against starting testosterone therapy.

Severe obesity

A named functional cause. The guideline is direct about the implication: "In some instances, educating patients that obesity or opioids may be contributing to hypogonadism could motivate them to lose weight or discontinue narcotic pain medications." Obesity also lowers sex hormone-binding globulin, which drags total testosterone down without necessarily moving free testosterone.

Opioids, glucocorticoids and anabolic steroid withdrawal

All three appear on the Endocrine Society’s functional list, and the guideline says not to test a man during short-term use of medications that suppress testosterone. Anabolic steroid withdrawal in particular produces a profoundly low result that is a consequence of prior use, not a primary condition — and prescribing testosterone for it treats the suppression with more of what caused it.

Acute or systemic illness, organ failure, nutritional deficiency, excessive exercise

All named as functional causes, and all reasons the guideline gives for not drawing the sample at all until the man has recovered. A testosterone drawn during illness measures the illness.

Type 2 diabetes

Associated with low testosterone concentrations, and a condition in which the Endocrine Society tested whether treating the testosterone helps the diabetes and concluded it does not: it recommends against testosterone therapy as a means of improving glycaemic control. Low testosterone in a man with diabetes is a finding to investigate, not automatically a target.

A pituitary or hypothalamic lesion

The rare one, and the reason LH and FSH are not optional. A man with low testosterone and a low LH may have a prolactinoma or another sellar lesion. Treating his symptoms with testosterone relieves them and leaves the tumour undiagnosed.

What treatment means here

Numbers this page will not give you

Each of these is a figure other pages state confidently. Each is omitted here because no source we could open supports one.

How common is hypogonadism?

No figure is given because no defensible one exists. The AUA guideline opens its prevalence section with "The prevalence of testosterone deficiency in the American male population is difficult to quantify" and reports that across 40 studies in 37,565 men the estimate "ranged from 2-77%", concluding that inconsistent thresholds, populations and assays make "arriving at a definitive number of testosterone deficiency difficult". A range from 2% to 77% is not a prevalence; it is a measurement of how unsettled the definition is. Any site quoting you a clean percentage picked one study.

What free testosterone level is too low?

There is no published diagnostic threshold to give. The Endocrine Society states that "A harmonized reference range for FT has not been established, so reference ranges may vary considerably depending on the specific equilibrium dialysis method or the algorithm used to calculate FT", and directs clinicians to use the limits their own laboratory provides. This page therefore prints total testosterone thresholds and no free testosterone threshold, and our free testosterone calculator carries no reference range for the same reason.

What is a normal testosterone for my age?

No age-adjusted diagnostic threshold is printed because no body has established one. The harmonized reference range comes from healthy nonobese men aged 19 to 39 and the Endocrine Society applies it to all adult men; Travison and colleagues describe the choice between a young-men reference and an age-adjusted one as unresolved. Population centiles by age do exist and are published in full on our reference-range tool — but a centile is not a threshold, and a lower number does not become acceptable because a man is older.

How long should I wait between the two blood tests?

Neither guideline specifies an interval, and the AUA says why: "At this time, there is no definitive evidence indicating what the optimal time interval should be between the two separate tests." A number here would be invented.

What dose would I be on?

Nothing on this page is a dose. Dosing depends on a diagnosis that has not been made, a formulation that has not been chosen and monitoring that has not started. The labelled dose ranges are on our testosterone dosage chart, where they belong, next to the label text they come from.

Frequently asked questions

Can I tell from my symptoms whether I have low testosterone?

No, and the guidelines say so rather than merely implying it. The AUA requires both halves — "The clinical diagnosis of testosterone deficiency is only made when patients have low total testosterone levels combined with symptoms and/or signs" — and describes the symptoms as non-specific. The European Male Ageing Study tested 3,369 men and found that of six symptoms associated with testosterone level, only the three sexual ones — poor morning erections, low sexual desire and erectile dysfunction — held together as a syndrome; fatigue, low mood and poor concentration did not. The validated symptom questionnaires do no better: the ADAM questionnaire posts a specificity of 39% and the AMS 19%, which is why the AUA recommends against using them at all.

Is the cutoff for low testosterone 264 or 300 ng/dL?

Both, depending on whose guideline you read, and this page prints both rather than choosing. The Endocrine Society uses 264 ng/dL (9.2 nmol/L), the 2.5th centile of CDC-harmonized healthy nonobese men aged 19 to 39. The AUA uses 300 ng/dL (10.4 nmol/L) as "a reasonable cut-off in support of the diagnosis". The AUA itself notes that across medical societies the thresholds have ranged from 230 to 350 ng/dL. What both agree on matters more than the gap: a number below the line is not a diagnosis without symptoms or signs, and not without a second morning sample.

Why do I need two blood tests instead of one?

Because roughly a third of first results do not reproduce. The Endocrine Society puts it at "30% of men with an initial T concentration in the hypogonadal range have a normal T concentration on repeat measurement". Testosterone also swings with the clock — the AUA reports that in men aged 30 to 40, "Total testosterone values obtained at 4p.m. in men aged 30-40 years were 20-25% lower than measurements takes at 8a.m., while men aged 70 years experienced only a 10% decline between the two time points". Both guidelines therefore require two separate early-morning samples, and the AUA makes it a Strong Recommendation at Grade A.

Does the blood test have to be fasting?

The two guidelines contradict each other here, which is worth knowing before you argue with a phlebotomist. The Endocrine Society requires "two separate mornings when the patient is fasting", on the basis that glucose and food intake suppress testosterone. The AUA reviewed the same literature and concluded the opposite: the evidence "is particularly weak, and the Panel does not recommend that clinicians insist on fasting prior to testing". We suggest fasting, because skipping one breakfast is close to costless and the possible bias runs in the direction of over-diagnosis. If your sample was drawn unfasted, the AUA position means it is not wasted.

My lab says my testosterone is normal but I feel terrible. What does that mean?

First, the range printed on your report is not the diagnostic threshold. It is an interval for that laboratory’s own assay and sampled population, and the Endocrine Society warns that "Using the lower limit of the range established in local laboratories may not accurately identify men with hypogonadism". The spread between laboratories is not small: when 1,133 laboratories using 14 different assays measured the same sample from one hypogonadal man, results ran from 45 to 365 ng/dL. Second, and more likely, the symptoms have another cause. Depression, obstructive sleep apnoea, anaemia, thyroid disease and chronic stress all produce this picture, and the AUA names chronic stress, chronic fatigue and depression specifically as alternatives. A normal testosterone is a reason to keep investigating, not to stop.

How common is low testosterone in men?

This page does not give a percentage, because the published ones do not converge. The AUA guideline reports that across 40 studies covering 37,565 men aged 43 to 82, estimated prevalence "ranged from 2-77%", and concludes that differing thresholds, populations and assays make "arriving at a definitive number of testosterone deficiency difficult". Even the AUA’s narrower summary spans 2 to 50%. A site that gives you one figure — "one in four men over 30" is the usual one — has selected a study rather than summarised the evidence.

What is the difference between primary and secondary hypogonadism?

Primary is testicular failure: the testes cannot produce testosterone, so the pituitary pushes harder and luteinising hormone and follicle-stimulating hormone come back high. Secondary is a failure of the signal from the pituitary or hypothalamus, so LH and FSH are low or inappropriately normal despite low testosterone. One blood test separates them, and the AUA makes measuring LH a Strong Recommendation at Grade A. The distinction changes what happens next: unexplained secondary hypogonadism prompts prolactin, iron studies and sometimes pituitary imaging, and it is the branch on which a treatable pituitary lesion is found.

Can low testosterone be reversed without testosterone therapy?

Sometimes, and this is the part of the guideline most often left out of a sales consultation. The Endocrine Society separates organic hypogonadism — permanent structural or destructive causes — from functional hypogonadism, "caused by conditions that suppress gonadotropin and T concentrations but that are potentially reversible with treatment of the underlying etiology". Severe obesity, opioids, glucocorticoids, systemic illness, nutritional deficiency and some sleep disorders are all on the functional list. Where one of those is driving the result, treating it is the treatment — and starting testosterone instead suppresses your own production and your fertility while it runs.

Is testosterone therapy FDA-approved for age-related low testosterone?

No. The reference testosterone cypionate label lists two indications — primary hypogonadism and hypogonadotropic hypogonadism, both organic — and then states that "Safety and efficacy of DEPO-Testosterone (testosterone cypionate) in men with “age-related hypogonadism” (also referred to as “late-onset hypogonadism”) have not been established". The Endocrine Society separately suggests against routinely prescribing testosterone to all men 65 or older with low concentrations, while allowing individualised treatment after explicit discussion where symptoms and consistently low morning levels are both present.

Should I just order a testosterone test online to check?

Both guidelines advise against testing men who have no reason to be tested. The Endocrine Society recommends against routine screening of the general population, and the AUA says clinicians "should refrain from measuring testosterone levels in patients who are asymptomatic, do not exhibit signs related to low testosterone, or do not have any comorbid conditions that are associated with low testosterone". The arithmetic is the reason: in a population where the condition is uncommon, most results below a threshold are false alarms — and a false alarm here can end in a prescription that suppresses your own production. If you do have persistent symptoms, the test to ask for is a morning total testosterone with LH, FSH and SHBG, drawn twice, and read by someone who can examine you.

Sources

1. [1]Bhasin S, Brito JP, Cunningham GR, et al. Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2018;103(5):1715–1744. PMID 29562364 — abstract: "We recommend making a diagnosis of hypogonadism only in men with symptoms and signs consistent with testosterone (T) deficiency and unequivocally and consistently low serum T concentrations."
2. [2]Bhasin S, et al. Endocrine Society Clinical Practice Guideline, 2018 — full text. Recommendation 1.1 technical remark: "clinicians should measure total testosterone concentrations on two separate mornings when the patient is fasting"; Figure 1 footnote: "The lower limit of the normal total testosterone (TT) harmonized to the CDC standard in healthy nonobese young men is 264 ng/dL (9.2 nmol/L)"
3. [3]Mulhall JP, Trost LW, Brannigan RE, et al. Evaluation and Management of Testosterone Deficiency: AUA Guideline. J Urol. 2018;200(2):423–432 (Reviewed and Validity Confirmed 2024). Statement 1: "Clinicians should use a total testosterone level below 300 ng/dL as a reasonable cut-off in support of the diagnosis of low testosterone."
4. [4]Travison TG, Vesper HW, Orwoll E, et al. Harmonized Reference Ranges for Circulating Testosterone Levels in Men of Four Cohort Studies in the United States and Europe. J Clin Endocrinol Metab. 2017;102(4):1161–1173. PMID 28324103 — "In healthy nonobese men, 19 to 39 years, harmonized 2.5th, 5th, 50th, 95th, and 97.5th percentile values were 264, 303, 531, 852, and 916 ng/dL, respectively."
5. [5]Wu FCW, Tajar A, Beynon JM, et al. Identification of late-onset hypogonadism in middle-aged and elderly men. N Engl J Med. 2010;363(2):123–135. PMID 20554979 — "only the three sexual symptoms had a syndromic association with decreased testosterone levels"
6. [6]DEPO-Testosterone (testosterone cypionate) injection, solution — FDA label via DailyMed, Pharmacia & Upjohn, approval ANDA085635, setid cfbb53d4-b868-4a28-8436-f9112eb01c39. Indications and Usage: age-related hypogonadism is explicitly excluded